JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
·
2023
·
IF 2
Miao Qiao,Xin Hua,Yongjun Yuan,Xi Cao
This work attempts to achieve the enrichment of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in acylglycerols as well as biodiesel production by investigating the performance of various lipases in ethanolysis. The ethanolysis activities of five immobilized lipases in decreasing order were as follows: Lipozyme TL IM, Novozym 40086/Lipozyme RM IM, Novozym 435 and Rhizopus oryzae lipase immobilized on polypropylene (RO PP). EPA could be enriched to a certain content by Lipozyme TL IM, Novozym 40086, Lipozyme RM IM, and RO PP. The enrichment of DHA was achieved well by those four sn -1,3 regioselective lipases, and DHA contents in acylglycerols were the highest when Lipozyme TL IM and Novozym 40086 were used, reaching 2.87-fold and 2.81-fold of the initial content. However, Novozym 435 could not enrich EPA and DHA effectively. Fatty acid ethyl esters produced in this work contained abundant palmitic acid and palmitoleic acid, which could be ideal biodiesel considering their chain length. The competitive factors of five lipases towards DHA were all significantly higher than those towards EPA. When Lipozyme TL IM and Novozym 40086 achieved the maximum DHA contents, their DHA recoveries in acylglycerols reached 91.87% and 89.00%, respectively. The DHA recoveries were all significantly higher than the corresponding EPA recoveries in the reactions catalyzed by five lipases. Moreover, Lipozyme TL IM could be a potential lipase for the separation of EPA and DHA. This study may promote the full use of fish oil and broaden the application of lipases.
研究领域:
生物化学
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食品科学
·
酶工程
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产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2024
·
IF 5.2
Yushuai Sang,Mingze Yang,Hong Chen,Yongdan Li
Catalytic lignin solvolysis (CLS) holds promise for efficient lignin utilization, yielding small molecules with minimal or no char formation. However, the role of different active sites of catalyst in CLS are rarely discussed. Here, Ni catalysts on different supports, i.e., SiO 2 , Al 2 O 3 , MgO, and ZrO 2 , were prepared with the aim of manipulating the relative importance of metal and acid-base functionalities to investigate the role of different active sites in the enzymatic hydrolysis of lignin (EHL) ethanolysis. The main ether linkage, i.e., β-O-4, in EHL is cleaved without the participation of a catalyst. Metal sites suppress repolymerization through hydrogenating active intermediates, while acid and base sites facilitate the conversion of phenolic monomers into complex alkylated and etherified products and also promote repolymerization reactions. Among the catalysts, Ni/SiO 2 demonstrated the highest hydrogenation activity and yielded the most monomers (24.7 wt %) at 280 °C for 6 h under 2 MPa H 2 in ethanol. These findings shed light on the catalytic mechanisms in CLS, offering valuable insights for future catalyst design.
研究领域:
化学工程
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催化科学
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生物质利用
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产品关联
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2022
·
IF 6.056
Duan Zhou,Mouming Zhao,Jiankang Wang,Muniba Faiza,Xuefeng Chen,Junjie Cui,Ning Liu,Daoming Li
Punicic acid (PA)-enriched diacylglycerol (DAG) possesses both the beneficial effects of PA and DAG. However, few studies have focused on the preparation of PA-enriched DAG. Here, we report a novel and highly efficient method for the preparation of PA-enriched DAG through Lipozyme 435-catalyzed ethanolysis of pomegranate seed oil (PSO). Firstly, PSO was obtained through microwave-assisted extraction. Subsequently, four lipases were screened for their capability in the preparation of PA-enriched DAG through ethanolysis of PSO (containing 82.98% PA), and Lipozyme 435 was selected. Under the optimal conditions, the resultant mixture containing 32.86% DAG was obtained. Interestingly, Lipozyme 435 maintained superior operational stability after ten successive cycles. A scale-up reaction was then conducted under the optimized conditions and the purified product containing 51.83% DAG (containing 81.95% PA) was obtained. The final product with a low peroxide value (1.45 mmol/kg) and undetectable acid value reached edible quality. This is the first study for the preparation of PA-enriched DAG through ethanolysis and Lipozyme 435 exhibited superior capability and recyclability. Compared with other approaches for DAG preparation, this approach favored shorter reaction time and better quality of the product. This study provides useful information for further studies involving DAG preparation and modification of PSO.
研究领域:
食品科学
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生物化学
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DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2016
·
IF 4.917
Jing Yang,Liang Zhao,Chunze Liu,Yuanyuan Wang,Liyi Dai
Efficient catalytic ethanolysis and gasification of kraft lignin were conducted over a versatile supported catalyst Rh/La 2 O 3 /CeO 2 –ZrO 2 to give high-value aromatic alcohols and H 2 -rich gas. The removal of phenolic hydroxyl group was the most prevalent reaction, and importantly, almost no phenols, undesired char and saturating the aromatic ring were detected. Meanwhile, the feedstock and solvent both played key roles in H 2 generation that contributed to the hydrodeoxygenation of liquid components and made the whole catalytic process out of H 2 supply. Reusability tests of catalyst indicated that the crystalline phase transition and agglomeration of support, the loss of noble metal Rh and carbon deposition were the possible reasons for its deactivation in supercritical ethanol. Comparing with water, methanol and isopropanol system, ethanol was the only effective solvent for the depolymerization process.
研究领域:
化学工程
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能源科学
✓ 已验证
DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Zhan-Ku Li,Hai-Tao Wang,Hong-Lei Yan,Jing-Chong Yan,Zhi-Ping Lei,Shi-Biao Ren,Zhi-Cai Wang,Shi-Gang Kang,Heng-Fu Shui
Ethanolysis is an efficient approach for converting lignites into chemicals under mild conditions. However, yield of soluble portion from lignite ethanolysis is limited and product distribution cannot be well regulated. In this paper, a series of catalysts (MMgAlO x , M = Cu, Zn, Co, Ni) were prepared by a coprecipitation method. The catalysts were characterized by X-ray powder diffraction, high resolution transmission electron microscope, N 2 physisorption, and CO 2 - and NH 3 -temperature-programed desorption. The results show that the catalysts have layered and mesoporous structures with tunable acidity/basicity. Catalytic ethanolysis of Xilinguole lignite was performed and the resulting ethanol-soluble portions (ESPs) were analyzed with a Fourier transform infrared spectrometer, thermogravimetric analyzer, and gas chromatograph/mass spectrometer. The results suggest that except NiMgAlO x , other catalysts significantly increased the yields of the ESPs, especially CuMgAlO x and ZnMgAlO x , which is probably related to the amount of H 2 produced from ethanol. Four major platform chemicals, i.e., arenes, phenols, alcohols, and esters, can be produced via the catalytic ethanolysis. The catalysts have high ethanolysis activity and low hydrogenation ability and therefore aromatic rings can be reserved. Distribution of the platform chemicals could be tuned by altering the catalysts. In addition, possible pathways on the catalytic ethanolysis were proposed.
研究领域:
化学工程
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能源化学
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DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2022
·
IF 6.449
Mingxuan Fan,Wenxiu Jiang,Lingqian Tang,Mengqi Zhao,Qingrong Cheng,Lu Feng,Hanjun Wu,Zhiquan Pan,Hong Zhou
From the perspective of full utilization of biomass, a clean approach for the production of diosgenin from total saponins in Dioscorea zingiberensis C.H. Wright (DZW) was realized by preliminary separation and extraction. An alcoholysis approach was adopted to obtain diosgenin using a novel magnetic solid acid Fe 3 O 4 @SiO 2 -Pr-S-Pr-SO 3 H Pr = -(CH 2 ) 3 -) as the catalyst. The prepared solid acid has been fully characterized. The single factor methodology was used to optimize the process parameters. The optimum conditions were: 0.50 g Fe 3 O 4 @SiO 2 -Pr-S-Pr-SO 3 H, 6.0 mL ethanol, the reaction temperature 120 ℃, reaction time 7.0 h and the maximum yield of diosgenin was 24.18% which are higher than conventional hydrolysis with 1.5 M sulfuric acid indicating the high catalytic activity of the solid acids. In addition, the solid acid had good reusability. The LC-MS technique was applied to analyze the main steroidal saponins in total saponins and possible mechanisms and pathways of hydrolysis and alcoholysis processes. Alcoholysis by an as-prepared magnetic solid acid is clearly excellent in high efficiency and reusability. It is a promising strategy for the green production of diosgenin through a cleaner approach.
研究领域:
植物化学
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天然产物化学
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绿色化学
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产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2021
·Vol. 13
·期 4
·2933-2946
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IF 4.987
Zhao Sibo,Wang Zihua,Chang Chun,Li Pan,Xu Guizhuan,Pang Shusheng
A two-stage alcoholysis was developed for improved conversion of furfural residue (FR) into levulinic acid (LA) and methyl levulinate (ML). Mixed acids including 0.01 M of H 2 SO 4 and Al 2 (SO 4 ) 3 and methanol/water (50/50 v/v%) were identified as the suitable catalyst and reaction medium. The optimum alcoholysis conditions were 198 °C and 1.5 h for the 1st stage and then 163 °C and 1.3 h for the 2nd stage, and the maximum total yield of LA and ML can reach 25.64%. The reaction kinetics and possible conversion pathways for ML and LA production were proposed. On the basis, HCOOH/H 2 O 2 pretreatment was screened for the pretreatment of FR, which increased the cellulose content of FR from 40.01 to 71.91%. The maximum total yield of LA and ML from pretreated FR was 44.96% under the optimum conditions of 195 °C and 1.9 h for the 1st stage and then 166 °C and 1.1 h for the 2nd stage, which was 16.09% higher than that of isothermal alcoholysis. The reusability tests showed that the Al 2 (SO 4 ) 3 was stable and can be reused at least 5 times. This study developed a new method for high-value utilization of FR and cleaner production of LA and ML.
研究领域:
化学工程
·
可再生能源
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产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 93
·90232-90238
·
IF 3.289
Xiao-Fang Liu,Hu Li,Heng Zhang,Hu Pan,Shan Huang,Kai-Li Yang,Song Yang
Catalytic ethanolysis of furfuryl alcohol (FA) to ethyl levulinate (EL) with MIL-101(Cr)–SO3H, prepared by simple one-pot hydrothermal treatment, is presented for the first time. The as-prepared catalyst with high surface area, hydrothermal and chemical stability, good dispersion, and feasible accessibility of –SO3H Brønsted acid sites was found to show superior performance to other sulfonic acid-functionalized solid catalysts. Besides the special textural properties, the obtained good catalytic activity of 79.2% EL yield and 100% FA conversion were also dependent on the density and strength of the Brønsted acid and the reaction parameters. A slight loss of catalytic activity after five consecutive recycles and the hot filtration experiment confirmed the good stability of MIL-101(Cr)–SO3H. Two coexisting reaction paths for the ethanolysis of FA to EL catalyzed by MIL-101(Cr)–SO3H were proposed, wherein 2-ethoxymethylfuran (2-EMF) was observed to be the dominant intermediate.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Guang-Hui Liu,Yu-Hong Kang,Yong Gao,Yan-Jun Li,Xiang-Rong Ma,Rui Dang,Long Yan,Wei-Wei Yan,Hong-Cun Bai,Zhi-Min Zong,Xian-Yong Wei
An in-situ and ex-situ cascade upgrade strategy was designed and used for upgrading Dahuangshan lignite-derived soluble mixtures (LDSMs) to obtain value-added chemicals and clean liquid fuels (CLFs), respectively. In the H 2 -free catalytic ethanolysis, Ni/mordenite can effectively activate ethanol and promote the transfer of various free radicals including H·, CH 3 CH 2 ·, and CH 3 CH 2 O·, which synchronously facilitates the cleavage of bridged bonds in Dahuangshan lignite and the in-situ removal of heteroatoms (HAs) from LDSMs. As a result, the total yield of LDSMs increased from 40.6 to 66.5 wt%, wherein that of ethanol-soluble portion (ESP) increased from 21.4 to 32.4 wt%. Interestingly, alkanes and arenes with higher relative content (RC, 38.1%) were detected in ESP C (for catalytic ethanolysis), while arenols (24.7%) dominate ESP N (for ethanolysis). The analysis with a quadrupole exactive orbitrap mass spectrometer further confirmed the significant decrease in the relative abundance of HAs, especially O x class species, in ESP C . In addition, ESP N and ESP C with different properties were further used for enriching derived chemicals and for obtaining CLFs by catalytic hydroconversion (CHC), respectively. After the CHC, the total RCs of alkanes and cyclanes in the soluble portion (SP) are as high as 71.3%, and the content of HA-containing organic compounds was further decreased. Therefore, such SP containing less HAs is an attractive CLF precursor. A ternary mixed solvent was also designed for rapidly separating the SP from ESP N . The total RC of alkanes and arenes in PE 5 as well as arenols in M 5 are as high as 79.4 and 70.9%, respectively. Molecular dynamics simulations were further used to reveal the rapid enrichment mechanisms with ternary mixed solvents.
研究领域:
化学工程
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能源科学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2013
·Vol. 110
·期 1
·31-39
·
IF 1.104
Zhang Tiantian,Zhang Xiaoli,Li Hongya,Bai Weili,Zhao Binxia
Anhydrous ethanol and choline hydroxide, which are friendlier to human beings, were applied in the process for preparing l -α-glycerophosphocholine. The mechanism of the ethanolysis of phosphatidylcholine catalyzed by choline hydroxide was proposed, the kinetics of the transesterification was evaluated under the catalyst concentration range of 0.006–0.018 mol/L and the temperature range of 293.15–323.15 K. The experimental data were well described by the pseudo-first order equation. The effects of nucleophilic reagent, concentration of catalyst, ethanol-to-oil molar ratios and the temperature were investigated, and the calculated activation energy was 24.28 kJ/mol.
研究领域:
生物化学
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食品科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2019
·
IF 4.888
Zhe Wen,Zewei Ma,Fuhang Mai,Fei Yan,Linhao Yu,Meng Jin,Yushuai Sang,Yunfei Bai,Kai Cui,Kai Wu,Mengmeng Chen,Hong Chen,Yongdan Li
The catalytic ethanolysis of microcrystalline cellulose in supercritical ethanol is examined over a sulfonated hydrothermal carbon catalyst (SHTC). SHTC is amorphous carbon containing −OH, −COOH and −SO 3 H groups with total acidity of 7.15 mmol/g and −SO 3 H acidity of 1.72 mmol/g. SHTC shows high catalytic activity towards the ethanolysis of cellulose in supercritical ethanol. Complete conversion of microcrystalline cellulose with high yields of ethyl levulinate and ethyl glucoside is obtained. The reaction temperature, time and catalyst amount have significant effects on the catalytic performances of SHTC. Appropriate reaction time and less catalyst amount are favorable for the production of ethyl glucoside, while prolonged reaction time and appropriate catalyst amount favor the production of ethyl levulinate. The highest yield of ethyl glucoside as 420.9 mg/g cellulose is obtained over 0.1 g SHTC at 245 ºC for 1 h. The highest yield of ethyl levulinate as 817.6 mg/g cellulose is achieved over 0.3 g SHTC at 245 ºC for 1 h. SHTC shows good stability in the recycle experiments with slight loss of catalytic activity.
研究领域:
生物化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Hengyu Hao,Yuya Abe,Haixin Guo,Xiao Zhang,Richard Lee Smith Jr
Bifunctional Lewis (L) acid (Ni- or Hf-) site–Brønsted (B) acid catalysts designed to promote transfer hydrogenation reactions were prepared via hydrothermal and solvothermal methods using safe mixed solvents and sustainable precursors. By using N,N-dimethylformamide as a basis for the desired basicity, mixed solvents could be identified that allowed catalysts to be prepared with tunable ratios of Lewis to Brønsted acid sites (L/B). The as-prepared catalysts promoted transfer hydrogenation of furfural and ethanolysis to form ethyl levulinate (EL) using ethanol as a solvent and hydrogen donor source. Among the catalysts, sulfonated Hf-catalysts prepared with a cyclopentanone/formic acid mixed solvent (Hf-CPN/FA) with an L/B ratio of 6.4 gave 95% furfural conversion with 51.9% yield of EL, while the sulfonated Hf catalyst prepared with a cyclopentanone/γ-valerolactone mixed solvent (Hf-CPN/GVL) with a total Lewis and Brønsted acid site amount of 85.1 μmol/g gave 100% furfuryl alcohol (FAL) conversion with 72.5% yield of EL. Brønsted acid sites promoted reversible acetalization of furfural with ethanol into 2-furaldehyde diethyl acetal, while Lewis acid sites promoted furfural transfer hydrogenation into FAL and EL and further conversion into γ-valerolactone. The methods developed in this work eliminate dipolar aprotic solvents and harsh acids used in catalyst synthesis and allow sustainable production of EL from biomass-related chemicals.
研究领域:
化学工程
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催化
·
绿色化学
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有机化学
·
生物质转化
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）